From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96CB4C2BA1B for ; Mon, 6 Apr 2020 15:28:09 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6AC6A248A3 for ; Mon, 6 Apr 2020 15:28:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AC6A248A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 3FE5087F7F; Mon, 6 Apr 2020 15:28:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HqAh7cUv3Xw3; Mon, 6 Apr 2020 15:28:07 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id CCE6A87CE1; Mon, 6 Apr 2020 15:28:07 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id BF827C1AE2; Mon, 6 Apr 2020 15:28:07 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id DFB44C0177 for ; Mon, 6 Apr 2020 15:28:06 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id D4CB9884BB for ; Mon, 6 Apr 2020 15:28:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YW+xLPienZea for ; Mon, 6 Apr 2020 15:28:04 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by hemlock.osuosl.org (Postfix) with ESMTPS id CDA24884A7 for ; Mon, 6 Apr 2020 15:28:04 +0000 (UTC) IronPort-SDR: MA51KXUxWaH/0xvbsAL8vHn7vu4ZSbZj4Os8/dyHBnysAvYqVwpjEedHMIyfm9nsAHatZADECP gGU3mYrLDIRA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Apr 2020 08:28:04 -0700 IronPort-SDR: Efs95U23jeH5LyAWlbkYBzqgSSSM63gsDcZ26TWAsvxc8ljsGjmt2X/LBX0e3+bfhfGMW9dJGT qyqRUyXjC8jg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,351,1580803200"; d="scan'208";a="254145738" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga006.jf.intel.com with ESMTP; 06 Apr 2020 08:28:03 -0700 Date: Mon, 6 Apr 2020 08:33:53 -0700 From: Jacob Pan To: Jean-Philippe Brucker Subject: Re: [PATCH 05/10] iommu/ioasid: Create an IOASID set for host SVA use Message-ID: <20200406083353.73efda5b@jacob-builder> In-Reply-To: <20200401135316.GF882512@myrica> References: <1585158931-1825-1-git-send-email-jacob.jun.pan@linux.intel.com> <1585158931-1825-6-git-send-email-jacob.jun.pan@linux.intel.com> <20200401135316.GF882512@myrica> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: "Tian, Kevin" , Raj Ashok , Jean-Philippe Brucker , LKML , iommu@lists.linux-foundation.org, Alex Williamson , David Woodhouse , Jonathan Cameron X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Jean, On Wed, 1 Apr 2020 15:53:16 +0200 Jean-Philippe Brucker wrote: > On Wed, Mar 25, 2020 at 10:55:26AM -0700, Jacob Pan wrote: > > Bare metal SVA allocates IOASIDs for native process addresses. This > > should be separated from VM allocated IOASIDs thus under its own > > set. > > > > This patch creates a system IOASID set with its quota set to > > PID_MAX. This is a reasonable default in that SVM capable devices > > can only bind to limited user processes. > > Yes realistically there won't be more than PID_MAX_DEFAULT=0x8000 > bound address spaces. My machine uses a PID_MAX of 4 million though, > so in theory more than 0x8000 processes may want a bond. Got it, I assume we can adjust the system set quota as necessary. > On Arm the > limit of shared contexts per VM is currently a little less than > 0x10000 (which is the number of CPU ASIDs). > I guess shared contexts means shared address? then it makes sense #IOASID < #ASID. > But quotas are only necessary for VMs, when the host shares the PASID > space with them (which isn't a use-case for Arm systems as far as I > know, each VM gets its own PASID space). Is there a host-guest PASID translation? or the PASID used by the VM is physical PASID? When a page request comes in to SMMU, how does it know the owner of the PASID if PASID range can overlap between host and guest? > Could we have quota-free IOASID sets for the host? > Yes, perhaps just add a flag such that the set has its own namespace. You mean have this quota-free IOASID set even co-exist with VMs? I still don't get how PRQ works. That is not the use case for VT-d in that we have to have system-wide allocation for host PASIDs. We have enqcmd which can take a PASID from the per task MSR and deliver to multiple devices, so even though the PASID table is per device the PASID name space must be global. > For the SMMU I'd like to allocate two sets, one SVA and one private > for auxiliary domains, and I don't think giving either a quota makes > much sense at the moment. I agree we don;t need the quota if we don't support guest SVA at the same time. So the sva set and aux_domain set PASIDs have their own namespaces? > There can be systems using only SVA and > systems using only private PASIDs. I think it should be > first-come-first-served until admins want a knob to define a policy > themselves, based on cgroups for example. > > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/intel-iommu.c | 8 +++++++- > > drivers/iommu/ioasid.c | 9 +++++++++ > > include/linux/ioasid.h | 9 +++++++++ > > 3 files changed, 25 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/intel-iommu.c > > b/drivers/iommu/intel-iommu.c index ec3fc121744a..af7a1ef7b31e > > 100644 --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -3511,8 +3511,14 @@ static int __init init_dmars(void) > > goto free_iommu; > > > > /* PASID is needed for scalable mode irrespective to SVM */ > > - if (intel_iommu_sm) > > + if (intel_iommu_sm) { > > ioasid_install_capacity(intel_pasid_max_id); > > + /* We should not run out of IOASIDs at boot */ > > + if (ioasid_alloc_system_set(PID_MAX_DEFAULT)) { > > + pr_err("Failed to enable host PASID > > allocator\n"); > > + intel_iommu_sm = 0; > > + } > > + } > > > > /* > > * for each drhd > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 6265d2dbbced..9135af171a7c 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -39,6 +39,9 @@ struct ioasid_data { > > static ioasid_t ioasid_capacity; > > static ioasid_t ioasid_capacity_avail; > > > > +int system_ioasid_sid; > > +static DECLARE_IOASID_SET(system_ioasid); > > + > > /* System capacity can only be set once */ > > void ioasid_install_capacity(ioasid_t total) > > { > > @@ -51,6 +54,12 @@ void ioasid_install_capacity(ioasid_t total) > > } > > EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > > > +int ioasid_alloc_system_set(int quota) > > +{ > > + return ioasid_alloc_set(&system_ioasid, quota, > > &system_ioasid_sid); +} > > +EXPORT_SYMBOL_GPL(ioasid_alloc_system_set); > > I think this helper could stay in the VT-d driver for the moment. If > the SMMU driver ever implements auxiliary domains it will use a > private IOASID set, separate from the shared IOASID set managed by > iommu-sva. Both could qualify as "system set". > Sounds good. Perhaps remove the special "system set". SVA code, VFIO, VT-d, or SMMU driver can all allocate their own sets. So to meet both SMMU and VT-d requirements, we should do: 1. add an IOASID_PRIVATE flag to ioasid_alloc_set(), indicating this is a private set 2. All APIs operate on the set_id accordingly, e.g. ioasid_find() will only search within the private set. Private set is excluded from from global search (VT-d needs this in PRQ). Since VT-d already needs private PASIDs for guest SVM where GPASID!=HPASID, I feel we can just reuse the per ioasid_set Xarray for both quota-free private set and guest set. Thanks for the feedback! Jacob > Thanks, > Jean > > > + > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 8c82d2625671..097b1cc043a3 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -29,6 +29,9 @@ struct ioasid_allocator_ops { > > void *pdata; > > }; > > > > +/* Shared IOASID set for reserved for host system use */ > > +extern int system_ioasid_sid; > > + > > #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 } > > > > #if IS_ENABLED(CONFIG_IOASID) > > @@ -41,6 +44,7 @@ int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); void > > ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_attach_data(ioasid_t ioasid, void *data); > > void ioasid_install_capacity(ioasid_t total); +int > > ioasid_alloc_system_set(int quota); int ioasid_alloc_set(struct > > ioasid_set *token, ioasid_t quota, int *sid); void > > ioasid_free_set(int sid, bool destroy_set); int > > ioasid_find_sid(ioasid_t ioasid); @@ -88,5 +92,10 @@ static inline > > void ioasid_install_capacity(ioasid_t total) { > > } > > > > +static inline int ioasid_alloc_system_set(int quota) > > +{ > > + return -ENOTSUPP; > > +} > > + > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu